LECTURES 



ON THE 



ELEMENTS OF COMPARATIVE ANATOMY. 



LECTURE I. 



ON THE CLASSIFICATION OF ANIMALS. 



THE GREGARINIDA, RIIIZOPODA, SPONGIDA, AND INFUSORIA. 



By the classification of any series of objects, is meant the 

 actual, or ideal, arrangement together of those which are like 

 and the separation of those which are unlike ; the purpose of 

 this arrangement being to facilitate the operations of the mind 

 in clearly conceiving and retaining in the memory, the cha- 

 racters of the objects in question. 



Thus, there may be as many classifications of any series of 

 natural, or of other, bodies, as they have properties or relations 

 to one another, or to other things ; or, again, as there are 

 modes in which they may be regarded by the mind : so that, 

 with respect to such classification as we are here concerned 

 with, it might be more proper to speak of a classification than 

 of the classification of the animal kingdom. 



The preparations in the galleries of the Museum of this 

 College are arranged upon the basis laid clown by John Hunter, 

 whose original collection was intended to illustrate the modihca- 

 tions which the great physiological apparatuses undergo in the 



B 



